396 THE CAMBRIAN. [bull. 81. 



The sandstone, which is beneath the limestone from near Kingston, Upper Canada, 

 to St. Anne's, 26 miles northwest of Montreal (174 miles), is white, but with fer- 

 ruginous spots and clouds, hard, fine grained, without cement, and contains thick 

 layers of large and small nodules of crystalline quartz, disposed in horizonal lines. 

 It forms cliffs an hundred feet high in the Lake of the Thousand Islands, which rest 

 on the very small-grained gueiss (often a granite) which abounds so in the north and 

 northeast and passes largely and frequently into primitive white quartz rock, thus 

 disclosing a possible source of the sandstone and quartz nodules. Where clay is the 

 cement an argillaceous sandstone or graywacke is furnished. The former of these I 

 have never seen in contact with the inclined rocks. It occurs very distinctly in the 

 chasm of the Niagara, the lower strata of which (and particularly those on which 

 Queenston stands) are almost ferruginous clay. The nearest primitive is on the north 

 shore of Lake Simcoe, 90 miles off. From the nature of the organic remains and other 

 contents of the limestones covering this sandstone, I am inclined to believe the latter 

 to be the old red, which is often thus intermixed with argillaceous matters. At Dun- 

 kirk, on the south side of Lake Erie, Mr. Hulbert has bored through these rocks to the 

 depth.of C82 feet (117 feet below the surface of the Atlantic) and without meeting with 

 salt. The above observations apply to the fine sections in the bed of the Genesee 

 River ; but I have not sufficiently examined the fossils in the limestone of that locality. 

 Its sandstone has large but indistinct casts of what I suppose to be encrinites, but 

 which may be vegetable, but in either case resembling the Old Red sandstone. It 

 may be added that it is on the same level with and not very far from the sandstone 

 of the vicinity of Kingston; but similarity in level taken by itself is not an unerring 

 test of similarity in age. In one part of a district or lake granite, gneiss, etc., may 

 attain a giveu elevation and be there covered with graywacke only; while in an- 

 other and not very distant place these rocks may not rise to within some thousand 

 feet of that height, and be buried under all the succeeding strata up to the Crag 

 above the London clay. 1 



A conglomerate wholly calcareous occurs in situ near the foot of the Long Sault 

 of the river Ottawa, and at the Coteau du lac, 3 miles below Lake St. Francis, com- 

 posed of angular and rolled masses, sometimes very large, of fine granular limestone 

 light brown and blue, imbedded in a dark brown paste. A similar rock occurs with 

 the limestone about Poughkeepsie, in the State of New York, and at Aubigny, oppo- 

 site Quebec, interleaved with clay slate and graywacke, highly inclined, and having 

 a southwest direction. 2 



The elements of correlation suggested in the preceding quotations 

 include lithologic resemblance, similarity of level in a given area, strat- 

 igrapbic succession, and the presence of organic remains. 



At a later date Dr. Bigsby noticed in the conglomerates on the south 

 side of the St. Lawrence, opposite Quebec, the presence of trilobites, 

 encrinites, corrallites, and other fossils, and, on this account, considers 

 the formation the equivalent of the Carboniferous limestone of the 

 English geologists. 3 



James. — One of the earliest extended correlations in America is that 

 of Dr. Edwin James. 4 In his remarks on the sandstone of the western 

 part of the valley of the Mississippi he first describes in detail the red 

 sandstone. 5 He states that this rock is the lowest of the horizontal or 



1 Op. cit., pp. 78-80. 

 2 Op. cit, p. 81. 



8 On the geology of Quebec and vicinity. Proc. Geol. Soc. London, vol. 1, 1827, p. 38. 

 4 Remarks on the sandstone and Floetz trap formations of the western part of the valley of the 

 Mississippi. Am. PhiL Soc. Trans., vol. 2, new ser., 1821, pp. 191-215. 

 6 Op. cit., p. 204. 



